The baby’s father, Israel Soto, 30, was booked into San Diego Central Jail over the weekend on one charge of willful cruelty to a child resulting in injury/death. The mother, Jessica Quezada, 23, was booked into Las Colinas Detention Facility on charges of willful cruelty to a child resulting in death and possession of a controlled substance.

The parents, who live in a low-income housing apartment in El Cajon, each posted $100,000 bail on Monday afternoon.

They are now scheduled to appear in court on Tuesday, Aug. 6.

According to new details released by the El Cajon Police Department on Sunday morning, an investigation has revealed that the parents had left the baby in the car overnight after returning home from shopping on Friday. The car was parked at an apartment complex in the 500 block of North Mollison Avenue, where the family lives.

The baby -- now identified by the county medical examiner's office as Giovanni Soto -- was discovered unresponsive inside the hot vehicle around 1:30 p.m. on Saturday, and police were called to the scene.

Officers performed CPR on the infant and transported him to a local hospital, where little Giovanni died a short time later.

"Through the course of their investigation [officials] learned that the parents had gone shopping the previous afternoon, left the child in the car and another family member discovered the child at 1:30 p.m. the next day," explained Lt. Walt Miller with the El Cajon Police Department. “Overnight would be a long time. You don’t see that often.”

El Cajon PIO Monica Zech said the length of time the baby boy was left in the car, coupled with hot temperatures, made for a dangerous combination.

"In this particular case, it was an extreme case, of a child left overnight, not just a few hours," said Zech. "It gets to a point where heat stroke is very deadly, and that's definitely what happened in this case. Let alone the poor child was probably very hungry. At the same time, that poor child is just cooking, basically cooking in that car."

NBC 7 meteorologist Greg Bledsoe said it was 80-degrees in El Cajon on Saturday at 1:30 p.m., when the baby was found in the car.

El Cajon resident Larry Singleton, who lives in the same apartment complex as the baby’s parents, said he was shocked to discover the infant had been left in the car overnight.

The county medical examiner’s office will now determine the Giovanni’s exact cause of death.

Police say the Soto’s and Quezada’s three other children – ages 1, 2 and 3 – have been taken into protective custody by Child Protection Services.

According to a study from the Department of Geosciences at San Francisco University, there have been at least 24 deaths of children left unattended in vehicles so far this year. In 2012, that number was 33.